#include <cstdio>
#include <iostream>
#include <string>
#include <sstream>
#include <stack>
#include <algorithm>
#include <cmath>
#include <queue>
#include <map>
#include <set>
#include <cstdlib>
#include <bitset>

template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }

char ToUpper(char cX) { return toupper(cX); }
char Tolower(char cX) { return tolower(cX); }

const long long INF = 1LL << 60;
const long long MOD = 1000000007;

using namespace std;
typedef unsigned long long ull;
typedef  long long ll;

vector<ll> dp;

int main()
{
	ll k, n;
	cin >> k >> n;
	vector<ll>a(n);
	for (ll i = 0; i < n; i++) {
		cin >> a[i];
	}
	
	dp = vector<ll>(k + 1, 0);
	dp[0] = 1;
	for (ll i = 0; i <= k; i++) {
		for (ll j = 0; j < a.size(); j++) {
			if (i - a[j] >= 0) {
				dp[i] += dp[i - a[j]];
				dp[i] %= MOD;
			}
		}
	}
	cout << dp[k] << endl;
	return 0;
}